Recently we found that the surface partially nitrided high-purity Ti deposited film can be activated as a nonevaporable getter (NEG) by heating at 185 °C. In this study, we investigated the activation mechanism of surface partially nitrided high-purity Ti by using soft X-ray photoelectron spectroscopy (XPS) and angle resolved Hard X-ray Photoelectron Spectroscopy (HAXPES). Both XPS and HAXPES measurements show that most of the surface oxygen atoms diffuse into the Ti bulk by heating at 470 °C. Based on these results we proposed the following activation mechanism for the surface partially nitrided high-purity Ti film. When heated at 185 °C, oxygen atoms in the vicinity of the surface nitrogen atoms diffuse into the Ti bulk, creating a narrow path of oxygen deficiency sites along the diffusion route of the oxygen atoms. When returning to room temperature, hydrogen gas is slightly pumped through this oxygen deficiency path. When heated at 450 °C, most of the surface oxygen atoms diffuse into the Ti bulk, exposing a large area of metallic Ti on the surface. When returning to room temperature, it starts to pump reactive residual gases with high pumping speeds.

SPring-8-II is an upgrade project toward the 4th generation synchrotron light source to provide hard X-ray with nearly two-orders of magnitude higher brilliance than the current SPring-8. Low electron beam emittance less than 100 pm･rad for the high brilliance requires high gradient multi-pole magnets with a small bore radius and vacuum chambers with a narrow aperture. The SPring-8-II vacuum ducts passing through electron beam have a rhombic cross-section with a small dimension of 26.16 mm between opposing inner surfaces. Strong beam wake field due to the narrow aperture increases vacuum chamber heating, so its evaluation and countermeasures are an important issue. In particular, the heating of the sector gate valve (SGV) with RF shield structure inside, which requires high reliability, should be evaluated, and measures such as water cooling should be taken if necessary. In this presentation, we report the results of simulations using the Finite Element Analysis (FEA) code ANSYS to evaluate temperature rising at the SGV for SPring-8-II due to beam-induced heating and to determine whether forced cooling is necessary.

The APS-Upgrade Project (APS-U) built a new electron 1100 meter circumference storage ring within the original APS tunnel. APS-U’s new storage ring vacuum system is a complex assembly of over 2500 custom vacuum chambers. The vacuum pumping system is a hybrid combination of NEG-coated vacuum chambers, ion pumps, and uncoated chambers with NEG strip pumping. APS-U began operations in April 2024 and by early 2025 has successfully commissioned the vacuum system to achieve low UHV operating pressures which helped the machine reach key performance parameters and allows for reliable delivery of beam to the users with minimal downtime. The commissioning performance of the machine indicates the NEG coated chambers are performing reliably even with a relatively minimal bakeout and activation. This presentation will share results and analysis of the vacuum system commissioning and performance along with lessons learned from the installation and operations phases.

The demand for cost- and time-effective and customizable components for High Vaccum (HV) and Ultra-High Vacuum (UHV) has prompted exploration into the application of 3D-printing technology. This study investigates the viability of utilizing 3D-printed plastics in UHV by evaluating their outgassing properties. An extensive evaluation of 3D-printing materials was carried out, highlighting the best polymer candidates using two of the most common 3D-printing techniques, Fused Deposition Modelling and Stereolithography. Further experimental investigations were conducted to assess the selected 3D-printed plastics under UHV, focusing on their low outgassing and resistance to baking temperatures. Furthermore, residual gas analysis was used to evaluate the possible presence of contaminants. The findings suggest that certain 3D-printed plastics exhibit promising characteristics for use in HV and UHV systems, with notable examples including COC and PEEK along with Rigid 10K and Tullomer™. A comparison between machined and 3D-printed parts demonstrated that challenges such as porosity and surface roughness showed not to be a cause of great concern.

Subsequent to the commissioning of NSLSII, the Vacuum Group established a vertical magnetron coating facility to support continued NSLSII operations and research activities. Some of the early projects included titanium coating injection kicker ceramic chambers as well as NEG coating standard vacuum chambers. This coating facility was also used to apply copper-oxide coating to the APS-U Injection Strip-line Kickers to manage thermal loads. While these efforts proved successful, the coating system was upgraded with a moveable, higher field-strength water-cooled solenoid to allow small aperture coating of varying length. The upgraded facility was used to develop the titanium coating for the ALS-U injection kickers and will also be used to test small aperture NEG coatings for a potential upgrade to NSLSII. The coating system can now coat chambers up to 2m in length which will allow for photon stimulated desorption measurements here at NSLSII. The facility history and upgrade will be described in detail along with the results of the ALS-U coating effort.

The European XFEL (X-ray Free-Electron Laser) is a research facility that generates ultra-short X-ray flashes for scientific experiments across various fields. Operating at MHz repetition rates, it produces coherent femtosecond X-ray pulses with unprecedented brilliance in the energy range of 250 eV to 25 keV. The facility consists of a linear accelerator and three photon beamlines in underground tunnels. To protect the sensitive optical components, such as mirrors that guide the X-ray beam to the experimental stations, strict contamination control within the photon beamlines is essential. A cleanroom is therefore required to handle critical components, ensuring that all equipment near the mirrors remains particle-free. Many of these components must meet ultra-clean vacuum (UCV) and ultra-high vacuum (UHV) standards to prevent contamination. This poster presents a newly designed pumping station for cleanroom applications. It enables standard vacuum tests, including leak testing and residual gas analysis (RGA), while minimizing contamination risks. To maintain cleanroom integrity, the pumping station is housed in a separate technical room and features remote operation capabilities.

Recently we have developed a new NEG, oxygen-free Pd/Ti. The initial pumping speeds of the oxygen-free Pd/Ti thin film after baking at 150 °C were estimated to be 3.2 L s–1 cm–2 for H2 and 7.6 L s–1 cm–2 for CO at room temperature. The oxygen-free Pd/Ti deposition for vacuum chambers and components in soft X-ray beamlines of synchrotron radiation (SR) facility seems to be ideal because it can be partially activated by baking at 75 °C for 6 h , and its pumping speed does not decrease in the pressure region below 10–8 Pa. We applied oxygen-free Pd/Ti deposition for the first mirror (M1) test chamber of a soft X-ray branch in a new beamline BL-11 in the Photon Factory 2.5 GeV ring (Tsukuba, Japan). Then the mirror and mirror holder system were installed in the M1 test chamber. After pumping and baking at 90–110 °C for 52 hours, the pressure in the M1 test chamber reached 6.9 × 10–8 Pa. When the M1 test chamber was isolated from TMP the pressure was maintained at ca. 5 × 10–7 Pa. Analysis of residual gases in the oxygen-free Pd/Ti deposition M1 test chamber showed that amount of hydrocarbons were below detection limits and that major of the residual gas was H2.

For the ESS superconducting linac, a compact beam stop for [21, 100] MeV protons was designed instead of a bulky beam dump. Its mass is 60 kg, its length 1200 mm (perpendicular to the beamline), and the cylindrical beam-intercepting part fits into a CF160 flange. In the most demanding beam mode (40 MeV, 50 µs, 1 Hz, 62.5 mA), thermomechanical calculations predict a peak temperature of 685˚C in the graphite core that is enclosed in a shell of TZM (a Ti-Zr-Mo alloy). The beam stop is water-cooled, equipped with thermocouples and moved by a pneumatic actuator. The beam stop was manufactured by Proactive R&D in Spain and shipped under vacuum to ESS in Sweden. The assembly, tests and metrology measurements were performed in an ISO 5 cleanroom. During August 2024, the beam stop was installed with a dedicated cart in the ESS beamline, surrounded by a portable cleanroom to maintain a particle-free environment next to superconducting cavities. The results of the beam commissioning and the main challenges (e.g. ISO 5 requirements, unconventional brazing and demanding engineering tolerances) are summarized and useful to design future particle-free devices intercepting high-power beams.

ALBA is working on the ALBA II upgrade to transform the current storage ring, in operation since 2012, into a 4th-generation diffraction-limited synchrotron light source. The vacuum system is designed for a compact geometry with tight magnet apertures, where synchrotron power is distributed directly onto the chamber walls. Nevertheless, crotch absorbers will be used at key locations. Due to the low conductivity in such small chambers, the entire ring will be NEG coated to accelerate vacuum conditioning and achieve the required ultimate pressure. Most of the vacuum chambers of the 268.8 m long ring, divided into 16 arcs of 12.8 m each, will be made of OFHC-Cu or CuCrZr to dissipate synchrotron radiation and reduce resistive wall impedance. The chambers will have a nominal internal diameter of 16 mm, a minimum wall thickness of 1 mm, and clearances of up to 0.5 mm from magnet poles. Launched in 2021, the upgrade includes an R&D program focused on prototyping critical components. This contribution presents the overall vacuum system status, the design and production of vacuum prototypes, and initial component tests.

The SPring-8-II project, upgrading SPring-8 to a 4th generation light source, started in FY2024. SPring-8 will shut down after summer 2027 for removal of existing equipment and installation of new accelerator components. User operation is scheduled to resume in spring 2029. The project requires a vacuum system compatible with compact, reduced-aperture magnets, ensuring sufficient beam lifetime and operational flexibility. An efficient pumping system was introduced for lifetime assurance, localizing photon-stimulated desorption gas near distributed absorbers and utilizing closely placed NEG pumps. A low coupling impedance vacuum system was designed by optimizing chamber geometry etc. to enable various operation modes. Prior to the mass production of vacuum components, prototypes of the main vacuum chambers were fabricated and their performance was verified with magnet arrays. These tests confirmed procedures for rapid installation and vacuum commissioning excluding in-situ baking after installation, checked for interference with other equipment, and verified vacuum performance. We present the design progress and prototype verification results for the SPring-8-II vacuum system.

Achieving Ultra High Vacuum (UHV) conditions is crucial for accelerator or synchrotron design. This can be done by coating copper and stainless-steel beam pipes with TiZrV Non-Evaporable Getter (NEG) thin films. In this work, we present the development of a setup for coating 40 mm and 16 mm diameter and 1 meter long pipes, studying the effects of sputtering pressure and gas on the coating properties. The coated pipes have been characterized in a setup based on the aperture method and Monte Carlo simulations have been carried out to determine coating sticking factor. The elemental composition, structure, hydrogen pumping speed, and CO saturation have been evaluated.

In this contribution we present a compact differential pumping chamber with apertures ≥ 500 μm. It allows windowless operation for in-air sample environments as well as to connect low-quality in-vacuum sample environments to the beamline UHV vacuum section. To simplify the design, it was decided not to integrate a positioning system and to rely on machining tolerances. In the end, the assembly consists of just 7 parts: 1 main aluminium body, 3 threaded cylinders with apertures and 3 covers with link to pumping units to be assembled with viton seals. The overall footprint is restricted to 368mm on the beam axis.